Off-loading of processing from a processor blade to storage blades

ABSTRACT

A processor blade determines whether a selected processing task is to be off-loaded to a storage blade for processing. The selected processing task is off-loaded to the storage blade via a planar bus communication path, in response to determining that the selected processing task is to be off-loaded to the storage blade. The off-loaded selected processing task is processed in the storage blade. The storage blade communicates the results of the processing of the off-loaded selected processing task to the processor blade.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 12/356,030filed on Jan. 19, 2009, which is incorporated herein by reference in itsentirety.

BACKGROUND

1. Field

The disclosure relates to a method, a system, and an article ofmanufacture for the off-loading of processing from a processor blade tostorage blades.

2. Background

A blade system is a computational device in which a plurality of bladecomputational devices may be included. The blade system includes a bladeenclosure that holds the plurality of blade computational devices. Theblade enclosure may provide certain shared services, such as, power,cooling, networking, various interconnects and management services tothe plurality of blade computational devices. The blade enclosure mayperform many of the non-core services found in many computationaldevices. By locating these services in one place in the enclosure andsharing these services among the blade computational devices, theoverall utilization and organization of a blade system may be moreefficient in comparison to a non-blade system.

SUMMARY OF THE PREFERRED EMBODIMENTS

Provided are a method, a system, and an article of manufacture, whereina processor blade determines whether a selected processing task is to beoff-loaded to a storage blade for processing. The selected processingtask is off-loaded to the storage blade via a planar bus communicationpath, in response to determining that the selected processing task is tobe off-loaded to the storage blade. The off-loaded selected processingtask is processed in the storage blade. The storage blade communicatesthe results of the processing of the off-loaded selected processing taskto the processor blade.

In certain embodiments, the storage blade includes memory, wherein thememory of the storage blade is partitioned into a data cache that storesinput/output (I/O) data requested by a processor blade processor.Additionally, the memory of the storage blade is partitioned into acommunication cache that stores indicators to control communicationsbetween the processor blade and the storage blade to perform theoff-loading, the processing, and the communicating.

In further embodiments, a blade system includes the processor blade anda plurality of storage blades including the storage blade. The pluralityof storage blades and the processor blade are plugged into a chassisplanar of the blade system. The plurality of storage blades areconfigured to perform I/O operations with storage devices coupled to theplurality of storage blades. A storage blade processor included in thestorage blade has unused processor cycles that are utilized byoff-loading the selected processing task from the processor blade to thestorage blade. If the storage blade processor determines a need for I/Odata that is not available from within the storage blade whileprocessing the off-loaded selected processing task, a request for theI/O data is transmitted to the processor blade, wherein the processorblade then satisfies the request and transmits the I/O data via theplanar bus communication path to the storage blade processor.

In certain embodiments, the indicators are flags, and wherein the flagsset by the processor blade include at least:

a JOB_TRANSFERRING flag that indicates that the processor blade istransferring data and text of a job to the storage blade;a JOB_TRANSFER_COMPLETE flag that indicates that an image of the job hasbeen completely sent by the processor blade, and the storage blade mayexecute the job; anda TRANSFER_RESULTS flag that indicates that the storage blade shouldtransfer a final job image back to the processor blade.

In further embodiments, the indicators are flags, and wherein the flagsset by the storage blade include at least:

a CPU_READY flag that indicates that the storage blade is idle or belowa programmable threshold in processing activity such that the storageblade can feasibly accept a job from the processor blade and expect toexecute the job in a reasonable number of processor cycles;a CACHE_READY flag that indicates that there is enough available cachein the memory of the storage blade to run a processor blade job;a JOB_PROCESSING flag that indicates that the processor blade job iscurrently running in the storage blade;a JOB_PAUSE flag that indicates that the storage blade has pausedexecution of the job;a JOB_COMPLETE flag that indicates that the processor blade job hascompleted successfully; andan I/O_REQUEST flag that indicates that the processor blade job runningon the storage blade encountered an I/O instruction that is to beprocessed by the processor blade.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings in which like reference numbers representcorresponding parts throughout:

FIG. 1 illustrates a block diagram of a blade system, in accordance withcertain embodiments;

FIG. 2 illustrates a first flowchart that shows operations performed inthe blade system, in accordance with certain embodiments;

FIG. 3 illustrates a block diagram of data structures implemented in theblade system, in accordance with certain embodiments;

FIG. 4 illustrates a second flowchart that shows operations performed inthe blade system, in accordance with certain embodiments; and

FIG. 5 illustrates a block diagram that shows certain elements that maybe included in the blade system, in accordance with certain embodiments.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanyingdrawings which form a part hereof and which illustrate severalembodiments. It is understood that other embodiments may be utilized andstructural and operational changes may be made.

With the advent of powerful, low-cost, low-power microprocessors it maybe possible to carry our more processing in less time by using anoperating system executing on a storage processor. Recent trends intechnology show a fast rise in microprocessor capability but a slow risein storage media capability. This indicates a growing capability of astorage blade microprocessor to handle additional processing tasks notrelated to storage operations, including executing processes that havebeen off-loaded from a busy processor blade.

Certain embodiments off-load low priority or storage-intensiveprocessing to one or more storage blades connected on the same bladechassis. Direct communication between a processor blade and storageblade processors is utilized for tracking and utilizing idle processorsin storage blades to offload appropriate low-priority processes from theprocessor blade. Certain embodiments use the blade chassis backplane tomanage efficiently the communication between the processor blade and thestorage blades.

Certain embodiments exploit the rise in processor capabilities on thestorage blades included in a blade system. Communication speed on theblade system backplane may reach an exemplary speed of 8 GB/sec, whichmay be higher than an exemplary speed of 1.7 GB/sec available forcommunication to an external storage device. This speed provides anopportunity to off-load processes from the processor blade to storageblades via the planar bus communication path on the blade systembackplane.

Certain embodiments provide policies and mechanisms for:

(i) Partitioning the storage blade memory between I/O requests andoffloaded processes and data;(ii) Communicating code text and data between the processor blade andstorage blade processors;(iii) Prioritizing I/O request processing with processing of off-loadedjobs;(iv) Handling the I/O of the off-loaded process itself;(v) Ending off-loaded jobs when such jobs terminate or cannot becompleted;(vi) Taking advantage of the idle time of a storage blade processor;(vii) Offloading processes in the presence of regular system I/Orequests and other I/O requests;(viii) Efficient communication policies and mechanisms between processorblade and storage blade through the backplane in a blade chassis; and(ix) Exploiting microprocessor and operating system capabilities in thestorage blade to supplement processor blade computing capabilities.

Certain embodiments use spare cycles in the storage blade to offloadprocessor blade program execution when there is an appropriate jobavailable. The processor blade operating system has knowledge of thestorage blade processors that are available in a blade chassis orsystem. A path for communication between the processor blade and thestorage blade processors is also provided. A protocol is provided bycertain embodiments to manage this process efficiently.

In certain embodiments, when the processor blade operating systemdetermines that a process can be off-loaded to storage blade, theprocessor blade operating system communicates with the storage bladeprocessor and transmits the process code and any data to the storageblade. The storage blade executes the code and transmits the data backto processor blade. If the storage blade processor requires I/O data,the I/O request is transmitted as a request to the processor blade. Theprocessor blade then satisfies the I/O request from the memory of theprocessor blade or other I/O devices and transmits the data across thebackplane to the storage blade processor.

Exemplary Embodiments

FIG. 1 illustrates a block diagram of a blade system 100, in accordancewith certain embodiments. The blade system 100 is a computational devicethat includes a processor blade 102 and a plurality of storage blades104 a . . . 104 n. The plurality of storage blades 104 a . . . 104 n arecoupled to the processor blade 102 via a planar bus communication path106, wherein the planar bus communication path 106 is implemented in thechassis planar, i.e., the enclosure, of the blade system 100. Theplurality of storage blades 104 a . . . 104 n and the processor blade102 may be plugged into the chassis planar of the blade system 100. Theplurality of storage blades 104 a . . . 104 n are configured to performI/O operations with storage devices coupled to the plurality of storageblades 104 a . . . 104 n. A storage blade processor included in thestorage blade has unused processor cycles that are utilized byoff-loading selected processing tasks from the processor blade to thestorage blade. The storage blade processors 114 a . . . 114 n may alsobe referred to as storage blade controllers.

The processor blade 102 includes a processor 108, a processor bladeoperating system 110, and code 112 that may be executed in the processor108. Each storage blade includes at least a storage blade processor, amemory, a storage blade operating system, and code that may be executedby the storage blade processor. For example, storage blade 104 aincludes a storage blade processor 114 a, a memory 116 a (also referredto as main memory or storage blade cache), a storage blade operatingsystem 118 a, and code 120 a that may be executed by the storage bladeprocessor 114 a, and storage blade 104 n includes a storage bladeprocessor 114 n, a memory 116 n, a storage blade operating system 118 n,and code 120 n that may be executed by the storage blade processor 114n. The storage blades 104 a . . . 104 n are coupled to or includestorage devices such as disks. For example, storage blade 104 a mayinclude disks 121 a and storage blade 104 n may include disks 121 n. Inone exemplary embodiment, the storage blade processor 114 a included inthe storage blade 104 a has unused processor cycles that are utilized byoff-loading selected processing tasks from the processor blade 102 tothe storage blade 104 a. In another exemplary embodiment, the storageblade processor 114 n included in the storage blade 104 n has unusedprocessor cycles that are utilized by off-loading selected processingtasks from the processor blade 102 to the storage blade 104 n. Theoperating systems that are resident with the blade system 100 are awareof the storage blade processors that are available in the blade system100.

In certain embodiments, the memory 116 a (also referred to as mainmemory) of the storage blade 104 a is partitioned into a data cache 122a that stores I/O data requested by the processor blade processor 108from storage devices coupled to the storage blade 104 a. Additionally,the memory 116 a of the storage blade 104 a is partitioned into acommunication cache 124 a (also referred to as a comcache) that storesindicators to control communications between the processor blade 102 andthe storage blade 104 a to perform at least the off-loading ofprocessing tasks from the processor blade 102 to the storage blade 104and the associated processing operations and communication operations.

The plurality of storage blades 104 a . . . 104 n are configured toperform I/O operations with storage devices 121 a . . . 121 n coupled tothe plurality of storage blades 104 a . . . 104 n. A storage bladeprocessor, such as storage blade processor 114 a, included in thestorage blade 104 a has unused processor cycles that are utilized byoff-loading a selected processing task from the processor blade 102 tothe storage blade 104 a. The selected processing task that is off-loadedmay comprise low priority processes.

FIG. 2 illustrates a first flowchart that shows operations performed inthe blade system 100, in accordance with certain embodiments. Theoperations shown in FIG. 2 may be performed by executing the code 112included in the processor blade 102 along with the code (e.g., code 120a and/or 120 n) stored in at least one exemplary storage blade (e.g.,storage blade 104 a and/or 104 n).

Control starts at block 200 in which the processor blade 102 determineswhether a selected processing task is to be off-loaded to a storageblade (e.g., any of the storage blades 104 a . . . 104 n) forprocessing. The selected processing task is off-loaded (at block 202) tothe storage blade via the planar bus communication path 106, in responseto determining that the selected processing task is to be off-loaded tothe storage blade. For illustrative purposes it is assumed that theselected processing task is off-loaded to the storage blade 104 a. Inalternative embodiments the processing task may be off-loaded toadditional storage blades or to a different storage blade.

Control proceeds to block 204 in which the off-loaded selectedprocessing task is processed in the storage blade 104 a. The storageblade 104 a communicates the results of the processing of the off-loadedselected processing task to the processor blade 102. In certainembodiments if the storage blade processor 114 a determines a need forI/O data that is not available from within the storage blade 104 a whileprocessing the off-loaded selected processing task, a request for theI/O data is transmitted to the processor blade 102, wherein theprocessor blade 102 then satisfies the request and transmits the I/Odata via the planar bus communication path 106 to the storage bladeprocessor 114 a.

Therefore, FIGS. 1 and 2 illustrate certain embodiments in whichprocessing tasks are offloaded from a processor blade 102 to one or morestorage blades 104 a . . . 104 n via a planar bus communication path106. As a result, unused cycles in the storage blade processors 114 a .. . 114 n may be used to relieve processing load on the processor 108 ofthe processor blade 102.

FIG. 3 illustrates a block diagram 300 of data structures implemented inthe blade system 100, in accordance with certain embodiments. FIG. 3shows the memory 116 a of the storage blade 104 a (wherein the memory116 a is referred to as the storage blade memory 116 a) partitioned intoa communication cache 124 a (referred to as a comcache 124 a), a datacache 122 a, and buffers 302, 304 for holding the process data andprocess output. Messages are passed on the backplane between theprocessor blade 102 and the storage blades (e.g., storage blades 104 a,104 n).

Communication processes in the processor blade operating system 110 andthe storage blades 104 a . . . 104 n caused via the execution of thecode 112, 120 a . . . 120 n manage communication across the chassisbackplane, the sending and receiving of commands and I/O data requests.In one embodiment, the communication processes access low-levelbackplane signals directly to efficiently implement messagingoperations. In another embodiment, the communication processes usehigher-level transmission protocols to implement messages. Thecommunication processes may use standard adapter cards and/or directaccess to the transmission signals on the backplane of the bladechassis. In another embodiment, a copy service path in the blade system100 may be used to transmit data. In yet another embodiment, theprocessor blade operating system 110 may be used to transmit databetween the processor 108 and the blade storage comcaches 124 a . . .124 n. In certain embodiments, the protocol bits are implemented asmessages that are buffered and managed by the communication processes.The messages may also be encrypted for security purposes.

The comcache 124 a is organized into a data area and a set of flags (theflags may be implemented as bits) for communicating status between theprocessor blade 102 and the storage blades 104 a . . . 104 n. Theseflags are replicated in the operating system state of the processorblade 102 and in the storage blade processor 114 a and kept insynchronicity across the interface using the communication processes.The processor blade 102 may have multiple sets of flags, one for eachstorage blade that is available for jobs. Some of the flags associatedwith the storage blades 104 a . . . 104 n are set by the processor blade102 and may be acted on by the storage blades 104 a . . . 104 n, whileothers are set by the storage blades 104 a . . . 104 n and may be actedon by the processor blade 102.

The flags that may be set by the processor blade 102 include:

(1) JOB_TRANSFERRING 306 flag: indicates that the processor blade 102 istransferring the data and text of a job to a storage blade usingsequential or tagged messages on the backplane. The job may bemulti-threaded if the storage blade operating system supportsmulti-threading. The processor blade 102 keeps track of the locationmemory where the image resides. The communication process on the storageblade writes the messages sequentially into the comcache as an image forthe processor to execute. The JOB_TRANSFERRING 306 flag is set inresponse to the CPU_READY 308 and CACHE_READY 310 flags being both setby the exemplary storage blade 104 a and an extant job that is to beexecuted.(2) JOB_TRANSFER_COMPLETE flag: indicates that the job image has beencompletely sent by the processor blade 102, and the storage blade maybegin processing. This flag may trail the last message that comprisesthe job image. The JOB_TRANSFER_COMPLETE flag is set in response tosending the last byte of the image to the storage blade.(3) TRANSFER_RESULTS flag: indicates that the storage blade shouldtransfer the final job image back to the processor blade 102 throughsequential or tagged messages on the backplane. As the messages arereceived, the communication process on the processor blade 102 writesthe image back to the memory where the image resides. This flag is setin response to the JOB_COMPLETE message from the storage blade.(4) JOB_DONE flag: indicates that no job has been sent to the storageblade. It can also indicate that the latest job completed execution onthe storage blade and the resulting image has been or is being writtento memory, or that the job failed on the storage blade for reasons givenbelow. This flag is set in response to a RESULTS_TRANSFER_COMPLETE or anABORT message from the storage blade. If the ABORT message is received,the processor blade 102 executes the original image elsewhere and noimage is written back to memory.(5) I/O_REQUEST_COMPLETE flag: indicates that the prior I/O_REQUEST fromthe storage blade was completed and the I/O request result has beenobtained. A message includes the I/O request result, including write orread status, and read data.

The flags set by the storage blade (such as any of the storage blades104 a . . . 104 n) may include:

(1) CPU_READY flag 308: indicates that the storage blade is idle orbelow a programmable threshold in processing activity such that thestorage blade can feasibly accept a job from the processor blade 102 andexpect to execute the job in a reasonable number of processor cycles. Ifthe storage blade goes not-idle due to a burst of requests or crossesthe programmable threshold of I/O activity and a job is eitherprocessing or transferring in, the job activity can be aborted, (i.e.the ABORT flag sent to the processor blade 102 and the comcache 124 a isreinitialized). The job activity may also be assigned a lower priorityrelative to the I/O activity. This flag is set in response to a JOB_DONEmessage from the processor blade 102.(2) CACHE_READY flag 310: indicates that there is enough available cachein the storage blade memory to run a processor blade 102 job. This flagis set in response to a JOB_DONE message from the processor blade 102.(3) JOB_PROCESSING flag 312: indicates that a processor blade 102 job iscurrently running in the storage blade. This flag is set in response toa JOB_TRANSFER_COMPLETE flag from the processor blade 102.(4) JOB_COMPLETE flag: indicates that the job has completed successfullyand result data is ready to be transferred back to the processor blade102. This flag is set in response to the job exiting back to the storageblade operating system on completion of the job.(5) RESULTS_TRANSFERRING flag: indicates that the job image (text anddata) is being transferred back to the processor blade 102 usingsequential or tagged messages. If an I/O request comes in during thetime a job is being transferred in, it will either cause thetransferring job to be aborted, paused, or the I/O request may beprocessed and serviced at a higher priority than the process transfer.This flag is set in response to a TRANSFER_RESULTS message from theprocessor blade 102.(6) RESULTS_TRANSFER_COMPLETE flag: indicates that the last sequentialor tagged message of the final job image has been sent back to theprocessor blade 102. This message may follow the last byte of the imagesent to the processor blade 102. This flag is set when the last byte hasbeen sent.(7) JOB_PAUSE flag: indicates that the storage blade has suspendedexecuting the job due to processing of a higher priority I/O request, iswaiting on an I/O response from the processor blade 102, or for anyother reason. In certain embodiments, the processor blade 102 does notrespond to this message, although in other embodiments it may cause thestorage blade to abort the job.(8) ABORT flag: signals or interrupts the blade processor and indicatesthat the current transmitted or running job has been killed for one ofseveral reasons:

-   -   (a) The controller needs to service mainline I/O requests and        cannot service an offloaded job even in low priority.    -   (b) The CPU_READY or CACHE_READY bits are not set.    -   (c) The JOB_PROCESSING bit is already set for some other        processor blade 102 job.    -   (d) The JOB_TRANSFERRING bit is already set for some other        processor blade 102 job.    -   (e) Not enough space available on the memory of the storage        blade for the process text or data.    -   (f) Ran out of available cache RAM during execution of the        offloaded job on the stack or heap.    -   (g) Offloaded job attempted operation that accesses memory        outside the text, data, stack or heap available in the memory of        the storage blade for offloaded processes.    -   (h) Job is detected to be a thread of some other process not        resident in a storage blade process table.    -   (i) Job failed due to any number of segmentation, bad        instruction, or other traps.        (9) I/O_REQUEST flag: indicates that the job running on the        storage blade encountered an I/O instruction that may have to be        processed by the processor blade 102. The storage blade then        pauses (suspends) until an I/O_REQUEST_COMPLETE message is        received from the processor blade 102. The request type and        address are sent in the message to the processor blade 102, and        the processor blade 102 services the request as a normal I/O        request. The request status and data are then sent as an        I/O_REQUEST_COMPLETE message back to the storage blade. In        certain embodiments, this protocol is carried out even if the        requested I/O is obtained from the storage device associated        with this storage blade. If the request is to write data, then        the I/O_REQUEST contains the write data and the        I/O_REQUEST_COMPLETE message provides the status.

Other messages of increasing complexity and functionality are alsopossible, including allowing a storage blade processor 114 a to directlyaccess its own storage for local I/O requests.

As described above, I/O is handled by the processor blade 102 and thestorage blade using I/O_REQUEST and I/O_COMPLETE messages. In oneembodiment of the communication processes, the interface bits areorganized as I/O messages to and from particular addresses with tags anddata that are interpreted by the processor blade 102 and the storageblade as messages. In another embodiment, the I/O messages may beassumed to be sequential until some other message is received or thecalculated amount of data is received. In another embodiment, thecommunication processes may buffer more data in the comcache 124 a thanrequested, in anticipation of future requests.

In FIG. 3 certain transitions of the state of selected flags are shown.For example, when a job is available and readiness conditions are met(reference numeral 314) then in response to such conditions, the stateof certain flags (CPU_READY, CACHE_READY, JOB_PROCESSING) are shown in afirst state 316 of the comcache 124 a. However, when the process outputbuffer 302 is full, the job processing is completed, or readinessconditions are not met (reference numeral 318) then in response to suchconditions, the state of certain flags (CPU_READY, CACHE_READY,JOB_PROCESSING) are shown in a second state 320 of the comcache. In thesecond state 320 of the comcache the process output buffer and theprocess data buffer are both available for data caching (referencenumeral 322).

FIG. 4 illustrates a second flowchart 400 that shows operationsperformed in the blade system 100. FIG. 4 shows an exemplary process forexecuting a processor blade job on a storage blade. The execution modeland protocol using the flags described above are shown in FIG. 4.

The exemplary process may perform the following operations after theprocess is started at block 402:

(1) On initialization, the storage blade initializes (at block 404) itscomcache and sets the CPU_READY and CACHE_READY flags, which aretransmitted as messages across the backplane to the processor blade 102.All other flags are initialized to logic 0.(2) When the processor blade operating system 110 determines that alow-priority process can be executed on a storage blade, the processorblade operating system 110 monitors the readiness bits from thecomcache, CPU_READY and CACHE_READY. The storage blade monitors its CPUutilization and cache availability on a frequent, periodic basis. Userdefined and/or implementation specific thresholds for these two metricsare used as criteria for the storage blade to determine its willingnessto accept jobs from the processor blade 102. When the CPU utilizationfalls below its threshold the CPU_READY bit is set. When the availablecache memory rises above its threshold, the CACHE_READY is set.(3) If these flags indicate the storage blade is ready, the processorblade 102 sets the JOB_TRANSFERRING flag and resets JOB_DONE if it isset. The processor blade 102 then sends the process image (code text anddata) as messages to the storage blade comcache. All normal I/O requestsmay be delayed until the job has completed transferring, and theJOB_TRANSFER_COMPLETE flag is set for one clock tick. In response toJOB_TRANSFERRING the storage processor resets (at block 406) CPU_READYand CACHE_READY.(4) On seeing JOB_TRANSFER_COMPLETE, the storage blade then sets theJOB_PROCESSING flag and begins executing the job, which may update dataor text portions of the memory image. If an I/O instruction isencountered, the storage blade suspends and sends an I/O_REQUEST messageto the processor blade 102 with a pointer to the appropriate buffer areain the comcache for any data. The processor blade 102 receives themessage, services the request and returns an I/O_REQUEST_COMPLETEresponse. Any data that is sent by the processor blade is buffered inthe comcache, and the job continues processing. When the job completes,the JOB_COMPLETE flag is set for one clock tick and at the same time theJOB_PROCESSING flag is reset by the storage blade (at blocks 408, 410).(5) When the processor blade 102 sees the JOB_COMPLETE flag, it sendsthe TRANSFER_RESULTS flag, which causes the storage blade to set itsRESULTS_TRANSFERRING flag and to send the image by messages to theprocessor blade 102 (at block 412).(6) When the image has been sent, the storage blade sets theRESULTS_TRANSFER_COMPLETE flag for one clock tick and resetsRESULTS_TRANSFERRING (at block 414).(7) When the processor blade 102 sees the RESULTS_TRANSFER_COMPLETEflag, the processor blade 102 sets the JOB_DONE flag and writes theimage data back to memory (at block 414)(8) When the storage blade sees the JOB_DONE flag, when it is ready, itsets the CPU_READY and CACHE_READY flags and the process ends (at block416).

During the transfer of the process to the storage blade cache, eitherthe process will fit in the reserved space in cache, or it will be toolarge and the storage blade will send the ABORT signal back to theprocessor blade operating system 110 indicating that it cannot acceptthe job. The reserved memory in the storage blade cache will then befreed to be used for normal I/O requests, and the JOB_PROCESSING orJOB_TRANSFERRING bits in the comcache will be cleared.

If the process fits in the reserved space of the storage blade cache,when the process has finished transferring, the storage blade clears theJOB_TRANSFERRING bit so that normal I/O requests can be serviced if theyhave been delayed. The storage blade processor then executes theprocess. The storage blade processor may then copy the resulting processimage to a buffer in another reserved portion of the cache memory. Oncethis output buffer is full, the output is messaged to the processorblade operating system 110, and the buffer is cleared or overwrittenwith another block of data from the process image. Once the processimage has been completely transferred back to the processor blade, thereserved buffer memory in the storage blade cache will be freed to beused for normal I/O requests.

If a mainline storage blade I/O request occurs while the general purposeprocess is executing in the storage blade, to avoid deadlock the storageblade may have to service that request. A context switch must occur, andeither the general purpose program is killed with an ABORT message tothe processor blade or its state is saved for later completion, and theJOB_PAUSE flag may be set.

The reading and writing of data between processor memory and storageblade is relatively slow compared to on-chip processing (but efficientusing the high-speed chassis backplane relative to clustering externalto the chassis), and the storage blade may not be optimized for generalpurpose programs. However, for low-priority processes and very busyprocessor cores, the storage blades may increase throughput for a bladesystem. The blade processor may track which processes have beeneffectively off-loaded to the storage blade processor and utilize thatknowledge in future operations.

Additional Embodiment Details

The described techniques may be implemented as a method, apparatus orarticle of manufacture involving software, firmware, micro-code,hardware and/or any combination thereof. The term “article ofmanufacture” as used herein refers to code or logic implemented in amedium, where such medium may comprise hardware logic [e.g., anintegrated circuit chip, Programmable Gate Array (PGA), ApplicationSpecific Integrated Circuit (ASIC), etc.] or a computer readable storagemedium, such as magnetic storage medium (e.g., hard disk drives, floppydisks, tape, etc.), optical storage (CD-ROMs, optical disks, etc.),volatile and non-volatile memory devices [e.g., Electrically ErasableProgrammable Read Only Memory (EEPROM), Read Only Memory (ROM),Programmable Read Only Memory (PROM), Random Access Memory (RAM),Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM),flash, firmware, programmable logic, etc.]. Code in the computerreadable storage medium is accessed and executed by a processor. Themedium in which the code or logic is encoded may also comprisetransmission signals propagating through space or a transmission media,such as an optical fiber, copper wire, etc. The transmission signal inwhich the code or logic is encoded may further comprise a wirelesssignal, satellite transmission, radio waves, infrared signals,Bluetooth, etc. The transmission signal in which the code or logic isencoded is capable of being transmitted by a transmitting station andreceived by a receiving station, where the code or logic encoded in thetransmission signal may be decoded and stored in hardware or a computerreadable medium at the receiving and transmitting stations or devices.Additionally, the “article of manufacture” may comprise a combination ofhardware and software components in which the code is embodied,processed, and executed. Of course, those skilled in the art willrecognize that many modifications may be made without departing from thescope of embodiments, and that the article of manufacture may compriseany information bearing medium. For example, the article of manufacturecomprises a storage medium having stored therein instructions that whenexecuted by a machine results in operations being performed.

Certain embodiments can take the form of an entirely hardwareembodiment, an entirely software embodiment or an embodiment containingboth hardware and software elements. In a preferred embodiment, theinvention is implemented in software, which includes but is not limitedto firmware, resident software, microcode, etc.

Furthermore, certain embodiments can take the form of a computer programproduct accessible from a computer usable or computer readable mediumproviding program code for use by or in connection with a computer orany instruction execution system. For the purposes of this description,a computer usable or computer readable medium can be any apparatus thatcan contain, store, communicate, propagate, or transport the program foruse by or in connection with the instruction execution system,apparatus, or device. The medium can be an electronic, magnetic,optical, electromagnetic, infrared, or semiconductor system (orapparatus or device) or a propagation medium. Examples of acomputer-readable medium include a semiconductor or solid state memory,magnetic tape, a removable computer diskette, a random access memory(RAM), a read-only memory (ROM), a rigid magnetic disk and an opticaldisk. Current examples of optical disks include compact disk—read onlymemory (CD-ROM), compact disk—read/write (CD-R/W) and DVD.

The terms “certain embodiments”, “an embodiment”, “embodiment”,“embodiments”, “the embodiment”, “the embodiments”, “one or moreembodiments”, “some embodiments”, and “one embodiment” mean one or more(but not all) embodiments unless expressly specified otherwise. Theterms “including”, “comprising”, “having” and variations thereof mean“including but not limited to”, unless expressly specified otherwise.The enumerated listing of items does not imply that any or all of theitems are mutually exclusive, unless expressly specified otherwise. Theterms “a”, “an” and “the” mean “one or more”, unless expressly specifiedotherwise.

Devices that are in communication with each other need not be incontinuous communication with each other, unless expressly specifiedotherwise. In addition, devices that are in communication with eachother may communicate directly or indirectly through one or moreintermediaries. Additionally, a description of an embodiment withseveral components in communication with each other does not imply thatall such components are required. On the contrary a variety of optionalcomponents are described to illustrate the wide variety of possibleembodiments.

Further, although process steps, method steps, algorithms or the likemay be described in a sequential order, such processes, methods andalgorithms may be configured to work in alternate orders. In otherwords, any sequence or order of steps that may be described does notnecessarily indicate a requirement that the steps be performed in thatorder. The steps of processes described herein may be performed in anyorder practical. Further, some steps may be performed simultaneously, inparallel, or concurrently.

When a single device or article is described herein, it will be apparentthat more than one device/article (whether or not they cooperate) may beused in place of a single device/article. Similarly, where more than onedevice or article is described herein (whether or not they cooperate),it will be apparent that a single device/article may be used in place ofthe more than one device or article. The functionality and/or thefeatures of a device may be alternatively embodied by one or more otherdevices which are not explicitly described as having suchfunctionality/features. Thus, other embodiments need not include thedevice itself.

FIG. 5 illustrates a block diagram that shows certain elements that maybe included in the blade system 100 in accordance with certainembodiments. The blade system 100 may also be referred to as a system500, and may include a circuitry 502 that may in certain embodimentsinclude at least a processor 504. The system 500 may also include amemory 506 (e.g., a volatile memory device), and storage 508. Thestorage 508 may include a non-volatile memory device (e.g., EEPROM, ROM,PROM, RAM, DRAM, SRAM, flash, firmware, programmable logic, etc.),magnetic disk drive, optical disk drive, tape drive, etc. The storage508 may comprise an internal storage device, an attached storage deviceand/or a network accessible storage device. The system 500 may include aprogram logic 510 including code 512 that may be loaded into the memory506 and executed by the processor 504 or circuitry 502. In certainembodiments, the program logic 510 including code 512 may be stored inthe storage 508. In certain other embodiments, the program logic 510 maybe implemented in the circuitry 502. Therefore, while FIG. 5 shows theprogram logic 510 separately from the other elements, the program logic510 may be implemented in the memory 506 and/or the circuitry 502.

Certain embodiments may be directed to a method for deploying computinginstruction by a person or automated processing integratingcomputer-readable code into a computing system, wherein the code incombination with the computing system is enabled to perform theoperations of the described embodiments.

At least certain of the operations illustrated in FIGS. 1-5 may beperformed in parallel as well as sequentially. In alternativeembodiments, certain of the operations may be performed in a differentorder, modified or removed.

Furthermore, many of the software and hardware components have beendescribed in separate modules for purposes of illustration. Suchcomponents may be integrated into a fewer number of components ordivided into a larger number of components. Additionally, certainoperations described as performed by a specific component may beperformed by other components.

The data structures and components shown or referred to in FIGS. 1-5 aredescribed as having specific types of information. In alternativeembodiments, the data structures and components may be structureddifferently and have fewer, more or different fields or differentfunctions than those shown or referred to in the figures. Therefore, theforegoing description of the embodiments has been presented for thepurposes of illustration and description. It is not intended to beexhaustive or to limit the embodiments to the precise form disclosed.Many modifications and variations are possible in light of the aboveteaching.

What is claimed is:
 1. A method, comprising: storing, in a storageblade, indicators that indicate whether the storage blade is idle orbelow a programmable threshold in processing activity and whether thereis enough available cache in the storage blade for executing a job; anddetermining whether to off-load at least one job from a processor bladeto the storage blade, based on the stored indicators.
 2. The method ofclaim 1, wherein selected indicators set by the processor bladeindicate: that the processor blade is transferring data and text of ajob to the storage blade; that an image of the job has been completelysent by the processor blade, and the storage blade may execute the job;and that the storage blade should transfer a final job image back to theprocessor blade.
 3. The method of claim 1, wherein selected indicatorsset by the storage blade indicate: that a processor blade job iscurrently running in the storage blade; that the storage blade haspaused execution of the processor blade job; that the processor bladejob has completed successfully; and that the processor blade job runningon the storage blade encountered an I/O instruction that is to beprocessed by the processor blade.
 4. The method of claim 1, wherein theindicators are set by the storage blade.
 5. The method of claim 1,wherein: a plurality of storage blades and the processor blade areplugged into a chassis planar of a blade system; and the plurality ofstorage blades are configured to perform Input/Output (I/O) operationswith storage devices coupled to the plurality of storage blades.
 6. Ablade system, comprising: a processor blade; and a storage blade coupledto the processor blade, wherein the blade system performs operations,the operations comprising: storing, in the storage blade, indicatorsthat indicate whether the storage blade is idle or below a programmablethreshold in processing activity and whether there is enough availablecache in the storage blade for executing a job; and determining whetherto off-load at least one job from a processor blade to the storageblade, based on the stored indicators.
 7. The blade system of claim 6,wherein selected indicators set by the processor blade indicate: thatthe processor blade is transferring data and text of a job to thestorage blade; that an image of the job has been completely sent by theprocessor blade, and the storage blade may execute the job; and that thestorage blade should transfer a final job image back to the processorblade.
 8. The blade system of claim 6, wherein selected indicators setby the storage blade indicate: that the processor blade job is currentlyrunning in the storage blade; that the storage blade has pausedexecution of the processor blade job; that the processor blade job hascompleted successfully; and that the processor blade job running on thestorage blade encountered an I/O instruction that is to be processed bythe processor blade.
 9. The blade system of claim 6, wherein theindicators are set by the storage blade.
 10. The blade system of claim6, wherein: a plurality of storage blades and the processor blade areplugged into a chassis planar of the blade system; and the plurality ofstorage blades are configured to perform Input/Output (I/O) operationswith storage devices coupled to the plurality of storage blades.
 11. Acomputer readable storage medium implemented in hardware, whereincomputer readable program code stored in the computer readable storagemedium causes operations when executed by a blade system having aprocessor blade and a storage blade, the operations comprising: storing,in the storage blade, indicators that indicate whether the storage bladeis idle or below a programmable threshold in processing activity andwhether there is enough available cache in the storage blade forexecuting a job; and determining whether to off-load at least one jobfrom the processor blade to the storage blade, based on the storedindicators.
 12. The computer readable storage medium of claim 11,wherein selected indicators set by the processor blade indicate: thatthe processor blade is transferring data and text of a job to thestorage blade; that an image of the job has been completely sent by theprocessor blade, and the storage blade may execute the job; and that thestorage blade should transfer a final job image back to the processorblade.
 13. The computer readable storage medium of claim 11, whereinselected indicators set by the storage blade indicate: that theprocessor blade job is currently running in the storage blade; that thestorage blade has paused execution of the processor blade job; that theprocessor blade job has completed successfully; and that the processorblade job running on the storage blade encountered an I/O instructionthat is to be processed by the processor blade.
 14. The computerreadable storage medium of claim 11, wherein the indicators are set bythe storage blade.
 15. The computer readable storage medium of claim 11,wherein: a plurality of storage blades and the processor blade areplugged into a chassis planar of a blade system; and the plurality ofstorage blades are configured to perform Input/Output (I/O) operationswith storage devices coupled to the plurality of storage blades.
 16. Asystem, comprising: a memory; and a processor coupled to the memory,wherein the processor performs operations, the operations comprising:storing, in a storage blade, indicators that indicate whether thestorage blade is idle or below a programmable threshold in processingactivity and whether there is enough available cache in the storageblade for executing a job; and determining whether to off-load at leastone job from a processor blade to the storage blade, based on the storedindicators.
 17. The system of claim 16, wherein selected indicators setby the processor blade indicate: that the processor blade istransferring data and text of a job to the storage blade; that an imageof the job has been completely sent by the processor blade, and thestorage blade may execute the job; and that the storage blade shouldtransfer a final job image back to the processor blade.
 18. The systemof claim 16, wherein selected indicators set by the storage bladeindicate: that the processor blade job is currently running in thestorage blade; that the storage blade has paused execution of theprocessor blade job; that the processor blade job has completedsuccessfully; and that the processor blade job running on the storageblade encountered an I/O instruction that is to be processed by theprocessor blade.
 19. The system of claim 16, wherein the indicators areset by the storage blade.
 20. The system of claim 16, wherein: aplurality of storage blades and the processor blade are plugged into achassis planar of a blade system; and the plurality of storage bladesare configured to perform Input/Output (I/O) operations with storagedevices coupled to the plurality of storage blades.